Funds are requested to help support a Symposium entitled "Mechanisms of Cellular Signal Transduction" and three State-of-the-Art Lectures at the 23rd Annual Meeting of the Society for the Study of Reproduction. The meeting will be held July 16-18, 1990, at the University of Tennessee, Knoxville, TN. All of the presentations were chosen to emphasize how cellular and molecular approaches are applicable to a wide range of problems in Reproduction Biology. The Symposium will emphasize selected aspects of signal transduction and will feature three researchers who are nationally and internationally recognized in this area. Dr. Lutz Birnbaumer will present the work he has pioneered on the multiple roles of G protein in transmembrane signal transduction. Dr. Marc Caron will discuss the structure, function, and regulation of catecholamine receptors, and Dr. David Garbers will address the molecular basis of signaling in the spermatozoon. The State-of-the-Art Lectures are designed to represent current and exciting areas of exploration in Reproduction Biology and to be of interest to a broad range of attendee. Dr. John Nilson will discuss molecular mechanisms underlying hormonal regulation and tissue-specific expression of the gonadotropin genes. Dr. Elizabeth Robertson will explain the use of embryonic stem cells (ES cells) to introduce mutations into the mouse germ line, and Dr. Patricia Saling will introduce new findings of how the egg regulates sperm function during gamete interaction. We anticipate that all of the presentations will provide an important educational benefit to the membership of our Society. Proceedings of the Symposium and State-of-the-Art Lectures will be published in The Biology of Reproduction.